Interfacially Bridging Covalent Network Yields Hyperstable and Ultralong Virus-Based Fibers for Engineering...

Area of Science:

• Biomaterials Science
• Nanotechnology
• Protein Engineering

Background:

• Tobacco mosaic virus (TMV) virus-like particles (VLPs) are promising nanoscale building blocks.
• Enhancing the structural integrity and assembly capabilities of VLPs is crucial for advanced applications.
• Covalent cross-linking strategies can improve the stability of protein-based nanomaterials.

Purpose of the Study:

• To develop a strategy for creating interfacially bridged covalent networks within TMV VLPs.
• To engineer TMV VLPs with enhanced robustness, structural stability, and assembly capabilities.
• To explore the application of these robust TMV VLPs in electrocatalysis for hydrogen evolution.

Main Methods:

• Site-directed mutagenesis was used to introduce cysteine residues (T103C, A74C) for disulfide bond formation.
• Systematic investigation of potential thiol conjugation sites (E50C to P54C) for longitudinal cross-linking.
• Characterization of VLP assembly, structural stability, and performance in harsh alkaline conditions.

Main Results:

• A novel TMV VLP (T103C-TMV-E50C-A74C) with interfacially bridged covalent networks was successfully engineered.
• The engineered TMV VLP exhibited unprecedented robustness, assembly capability, and structural stability, achieving the largest lengths reported to date.
• These fibers maintained integrity even under extremely alkaline conditions (pH 13).

Conclusions:

• The developed strategy effectively enhances TMV VLP properties through covalent cross-linking.
• The robust TMV VLPs are suitable for reducer-free synthesis of high-performance electrocatalysts.
• This work opens new avenues for utilizing engineered viral nanoparticles in harsh electrochemical environments, particularly for hydrogen evolution.